reentrant_memory_function.asm

; ASM File for the Nabla VM 
;     https://github.com/NablaVM
; - This file utilizes the special functionality of functional units along 
;   side yield's reentry functionality as a POC
;   for using them together as a memory storage unit

.file "memory_play"

.init main

.int64 exitflag     0
.int64 commandspace 0

<main:

    ; Setup memoru
    call memory 

    mov r0 $10
    stw $8(gs) r0

    mov r8 $1
    mov r9 $10

call_loop:

    ; Action
    call memory 

    ; -- Loop a few times to call memory
    add r8 r8 $1
    bne r8 r9 call_loop

    ; Close out memory
    mov r0 $1
    stw $0(gs) r0

    call memory

    exit
>

<memory:
    ; Init space
    mov r0 $0
    mov r1 $0
    mov r2 $10
init_top:

    ; zeroize stack space
    pushw ls r0

    ; Add to counter, loop until fin
    add r1 r1 $1
    blt r1 r2 init_top

execute_top:

    mov r1 $1       ; Check for exit flag
    ldw r0 $0(gs)   ; Load flag

    ; If memory space for exitflag is not 1, we continue
    bne r0 r1 continue

    ; If debug out shows this, we were asked to clear memory
    mov r0 $777

    ; If the flag is 1, then we return and everything is cleared
    ret
continue:

    ; load command
    ldw r0 $8(gs)

    ; Do some stuff specific to memory

    yield 

    ; Reentry should bring us here and will jump to execute_top
    mov r0 $500 ; Just to show in debug we reached here

    jmp execute_top

    ; We should never get here
    mov r0 $255
>